1. Field of the Invention
The present invention relates to a liquid ejection head and a method of producing a liquid ejection head that ejects liquid.
2. Description of the Related Art
Known liquid ejection heads include an element substrate that has a group of ejection ports through which liquid, such as ink, is ejected and energy generating elements corresponding to the ejection ports. Such a liquid ejection head further includes a contact portion through which electric signals and power for driving the energy generating elements from an ink jet recording apparatus body are received. Usually, the contact portion is connected to the element substrate by a flexible electrical wiring member.
When a support member, which is a part of a housing of the liquid ejection head, is connected to the element substrate, adhesive is applied to the support member, and then the element substrate is positioned with respect to the support member. The electrical wiring member and the element substrate are electrically connected to each other by an inner lead exposed from the electrical wiring member and connecting terminals provided on the element substrate. Then, the electrically connected portion is covered by a sealing material for protection. Because this sealing material needs to quickly fill small spaces, such as gaps in the electrically connected portion, a relatively low-viscous sealing material is often used.
Such a sealing material is provided in order to avoid contact with a side surface of the element substrate because expansion or contraction of the sealing material due to, for example, a change in environment exerts an external force on the element substrate. Recently, element substrates have been reduced in size in response to the demand for compact liquid ejection heads. Therefore, if a sealing material exerts an external force on such an element substrate, the element substrate may be deformed.
U.S. Pat. No. 7,240,991 discloses a method in which a wall made of another adhesive is provided to prevent a sealing material from flowing in side surfaces of an element substrate that are not provided with connecting terminals. In this method, after a wall made of another adhesive is provided between the connecting terminals of the element substrate and the side surfaces of the element substrate that are not provided with the connecting terminals, a sealing material is injected to cover the electrically connected portion, thereby preventing spreading of the sealing material.
However, because the configuration disclosed in U.S. Pat. No. 7,240,991 requires another adhesive to form a wall for preventing inflow of the sealing material, the component count increases. Furthermore, because this configuration requires steps of applying and curing this adhesive, the production cost of liquid ejection heads increases.